With the advent of thin walled metalwood golf club heads, the performance of metalwood clubs has improved considerably. By increasing the surface area of the striking face, using high strength alloys for its construction, and reducing its thickness to introduce a “trampoline” effect, club head designers have increased the efficiency of energy transfer from a metalwood club to a golf ball. As a result, the United States Golf Association (USGA) has imposed regulations to limit energy transferred from drivers to a golf ball by defining a maximum “characteristic time” (CT) that the clubface may remain in contact with a suspended steel weight impacting it. The maximum CT corresponds to a maximum “coefficient of restitution” (COR) for metalwood clubs. Currently, the maximum COR permissible by the USGA is 0.830.